diff options
| -rw-r--r-- | fs/btrfs/send.c | 137 |
1 files changed, 129 insertions, 8 deletions
diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c index 42e04cd3cd95..551294a6c9e2 100644 --- a/fs/btrfs/send.c +++ b/fs/btrfs/send.c @@ -100,6 +100,7 @@ struct send_ctx { u64 cur_inode_rdev; u64 cur_inode_last_extent; u64 cur_inode_next_write_offset; + bool ignore_cur_inode; u64 send_progress; @@ -5796,6 +5797,9 @@ static int finish_inode_if_needed(struct send_ctx *sctx, int at_end) int pending_move = 0; int refs_processed = 0; + if (sctx->ignore_cur_inode) + return 0; + ret = process_recorded_refs_if_needed(sctx, at_end, &pending_move, &refs_processed); if (ret < 0) @@ -5914,6 +5918,93 @@ out: return ret; } +struct parent_paths_ctx { + struct list_head *refs; + struct send_ctx *sctx; +}; + +static int record_parent_ref(int num, u64 dir, int index, struct fs_path *name, + void *ctx) +{ + struct parent_paths_ctx *ppctx = ctx; + + return record_ref(ppctx->sctx->parent_root, dir, name, ppctx->sctx, + ppctx->refs); +} + +/* + * Issue unlink operations for all paths of the current inode found in the + * parent snapshot. + */ +static int btrfs_unlink_all_paths(struct send_ctx *sctx) +{ + LIST_HEAD(deleted_refs); + struct btrfs_path *path; + struct btrfs_key key; + struct parent_paths_ctx ctx; + int ret; + + path = alloc_path_for_send(); + if (!path) + return -ENOMEM; + + key.objectid = sctx->cur_ino; + key.type = BTRFS_INODE_REF_KEY; + key.offset = 0; + ret = btrfs_search_slot(NULL, sctx->parent_root, &key, path, 0, 0); + if (ret < 0) + goto out; + + ctx.refs = &deleted_refs; + ctx.sctx = sctx; + + while (true) { + struct extent_buffer *eb = path->nodes[0]; + int slot = path->slots[0]; + + if (slot >= btrfs_header_nritems(eb)) { + ret = btrfs_next_leaf(sctx->parent_root, path); + if (ret < 0) + goto out; + else if (ret > 0) + break; + continue; + } + + btrfs_item_key_to_cpu(eb, &key, slot); + if (key.objectid != sctx->cur_ino) + break; + if (key.type != BTRFS_INODE_REF_KEY && + key.type != BTRFS_INODE_EXTREF_KEY) + break; + + ret = iterate_inode_ref(sctx->parent_root, path, &key, 1, + record_parent_ref, &ctx); + if (ret < 0) + goto out; + + path->slots[0]++; + } + + while (!list_empty(&deleted_refs)) { + struct recorded_ref *ref; + + ref = list_first_entry(&deleted_refs, struct recorded_ref, list); + ret = send_unlink(sctx, ref->full_path); + if (ret < 0) + goto out; + fs_path_free(ref->full_path); + list_del(&ref->list); + kfree(ref); + } + ret = 0; +out: + btrfs_free_path(path); + if (ret) + __free_recorded_refs(&deleted_refs); + return ret; +} + static int changed_inode(struct send_ctx *sctx, enum btrfs_compare_tree_result result) { @@ -5928,6 +6019,7 @@ static int changed_inode(struct send_ctx *sctx, sctx->cur_inode_new_gen = 0; sctx->cur_inode_last_extent = (u64)-1; sctx->cur_inode_next_write_offset = 0; + sctx->ignore_cur_inode = false; /* * Set send_progress to current inode. This will tell all get_cur_xxx @@ -5968,6 +6060,33 @@ static int changed_inode(struct send_ctx *sctx, sctx->cur_inode_new_gen = 1; } + /* + * Normally we do not find inodes with a link count of zero (orphans) + * because the most common case is to create a snapshot and use it + * for a send operation. However other less common use cases involve + * using a subvolume and send it after turning it to RO mode just + * after deleting all hard links of a file while holding an open + * file descriptor against it or turning a RO snapshot into RW mode, + * keep an open file descriptor against a file, delete it and then + * turn the snapshot back to RO mode before using it for a send + * operation. So if we find such cases, ignore the inode and all its + * items completely if it's a new inode, or if it's a changed inode + * make sure all its previous paths (from the parent snapshot) are all + * unlinked and all other the inode items are ignored. + */ + if (result == BTRFS_COMPARE_TREE_NEW || + result == BTRFS_COMPARE_TREE_CHANGED) { + u32 nlinks; + + nlinks = btrfs_inode_nlink(sctx->left_path->nodes[0], left_ii); + if (nlinks == 0) { + sctx->ignore_cur_inode = true; + if (result == BTRFS_COMPARE_TREE_CHANGED) + ret = btrfs_unlink_all_paths(sctx); + goto out; + } + } + if (result == BTRFS_COMPARE_TREE_NEW) { sctx->cur_inode_gen = left_gen; sctx->cur_inode_new = 1; @@ -6306,15 +6425,17 @@ static int changed_cb(struct btrfs_path *left_path, key->objectid == BTRFS_FREE_SPACE_OBJECTID) goto out; - if (key->type == BTRFS_INODE_ITEM_KEY) + if (key->type == BTRFS_INODE_ITEM_KEY) { ret = changed_inode(sctx, result); - else if (key->type == BTRFS_INODE_REF_KEY || - key->type == BTRFS_INODE_EXTREF_KEY) - ret = changed_ref(sctx, result); - else if (key->type == BTRFS_XATTR_ITEM_KEY) - ret = changed_xattr(sctx, result); - else if (key->type == BTRFS_EXTENT_DATA_KEY) - ret = changed_extent(sctx, result); + } else if (!sctx->ignore_cur_inode) { + if (key->type == BTRFS_INODE_REF_KEY || + key->type == BTRFS_INODE_EXTREF_KEY) + ret = changed_ref(sctx, result); + else if (key->type == BTRFS_XATTR_ITEM_KEY) + ret = changed_xattr(sctx, result); + else if (key->type == BTRFS_EXTENT_DATA_KEY) + ret = changed_extent(sctx, result); + } out: return ret; |